The invention relates to a device suitable for treating liquids, in particular contaminated water, which device comprises a treatment chamber and a liquid inlet and a liquid outlet connected to said treatment chamber, wherein a plurality of substantially parallel ultraviolet lamps are disposed in said treatment chamber, which ultraviolet lamps are arranged in substantially parallel planes and which are movable with respect to each other.
In a similar device known from German utility model no. 93.20.594.5 a plurality of ultraviolet (UV) lamps are disposed in the treatment chamber, wherein a fluid flowing through the treatment chamber, such as contaminated water, for example, is cleaned by means of the UV radiation emitted by said UV lamps.
In this prior art device the planes are pivotally connected near a first longitudinal side to a construction that can float on the water, whilst the second longitudinal side remote from said first longitudinal side rests on a bottom of the treatment chamber. When the water level in the treatment chamber rises, the construction will be moved in upward direction, with the planes taking up a different angle with respect to the bottom. The spacing between the planes slightly changes thereby.
The degree of contamination is determined by the dosage of ultraviolet radiation to which the liquid particles are exposed. The radiation emitted by an ultraviolet lamp depends on the age of the lamp, however. Moreover, the question whether water flowing past a UV lamp at some distance therefrom is irradiated with UV light furthermore depends on the spacing between the lamps and the transmission value of the liquid.
One drawback of the prior art device is the fact that in the case of a different transmission value of the liquid to be treated or of a reduced emission of UV light resulting from ageing of a lamp, only a limited change of the spacing between the planes can be effected, as a result of which not all liquid particles will be irradiated to a Sufficient degree and an optimum cleaning effect is not obtained.
The object of the invention is to provide a device by means of which the drawbacks of the prior art are avoided.
This objective is accomplished with the device according to the invention in that said planes can be translated with respect to each other only in a direction transversally to said planes whereby distances between a first and a second lamp of one plane to the closest lamp in another plane are always identical.
Since the lamps are movable with respect to each other in a direction transversely to the planes it is possible to adjust practically any desired distance between the lamps in dependence on the dosage of UV radiation that is minimally required. In this manner the desired liquid cleaning effect can be guaranteed.
Parallel planes can be moved relatively easily with respect to each other by mechanical, hydraulic and/or pneumatic means. Preferably, springs are disposed between the respective planes, whereby movement of the outer planes with respect to each other also causes the planes disposed therebetween to be moved, with all planes being spaced the same distance apart.
One embodiment of the device according to the invention is characterized in that the lamps of a first plane are staggered with respect to the lamps of the second plane disposed opposite said first plane.
As a result of the staggered arrangement of the lamps, an in particular if the lamps of one plane are disposed centrally between respective lamps of another plane, an adequate distribution of the radiation will be obtained irrespective of the spacing between the planes.
Yet another embodiment of a device according to the invention is characterized in that the planes extend substantially horizontally in use, wherein a plane disposed near the upper side is connected to an element that floats on the liquid to be treated.
As a result, the spacing between the planes is determined by the level of the liquid present in the treatment chamber. When the liquid level is relatively low, the force of gravity will cause the floating element to move in downward direction, as a result of which the planes will be positioned more closely together. When the liquid level in the chamber rises, the floating element will automatically move upwards and the planes will be moved further apart. In this manner it is possible to reduce the amount of liquid being supplied to the treatment chamber when treating a liquid having a relatively low transmission value, as a result of which the planes will automatically be moved towards each other and the spacing between the lamps will be reduced, so that in spite of the low transmission value a sufficiently high dosage of UV radiation will still be supplied to all liquid particles.